RS232 USER INSTRUCTIONS
Connect the device to a PC by using an RJ45 data cable, use your PC’s serial port assistant software to see the
working parameter of this device
Control command: READ
Baud rate: 9600
Data bit: 8
Stop bit: 1
Check bit: NONE
Control flow: NONE
NOTES
1. Input optical Power: For optimal performance, the received power should be between -7~+2 dBm. Receiver will
operate as low as -12 dBm Input power, however CNR will deteriorate as input power decreases. If input power is too
high, it will cause CTB and CSO deterioration. When received power is >3dBm (2mW), it may potentially damage the
optical receiver module.
2. RF output level: optical receiver’s RF output level is related to receive power and optical receiver’s RF drive level
(the modulation coefficient). Typically, as receive power increases or decreases by 1 dB, optical receiver’s RF output
level would increase or decrease 2 dB (1:2). If the Optical receiver’s RF drive level increases or decreases 1 dB, the
optical receiver’s RF output level would increase or decrease 1 dB (1:1).
3. CTB and CSO: RF output level too high will cause the CTB and CSO index to deteriorate. Shall output level
increase 1dB, and CTB would deteriorate 2dB, CSO would deteriorate 1.5dB. When adjusting optical receiver’s RF
output level, you should ensure the distortion index CTB≤-65dB, CSO≤-60dB.
ERROR AND REMEDY
No RF output
Check the power supply of the unit to determine whether it is normal.
Insert optical connector, if the RX-Low is showing a red light, or no optical power, you should use an optical
power meter to measure the optical power of the optical cable output connector. If optical power is normal, it
may not be seated well into the optical connector, (this unit adopts SC/APC), or optical receiver module may be
damaged, if damage is suspected, you should contact Maxcom and return for factory maintenance.
RF output level too low(<20dBmV)
Check received optical power to determine if too low. (<-12dBm)
RF output level too high causing the distortion index to be deteriorated
Check received optical power to determine if too high, such as >3dBm you should install an optical attenuator.
Check the head-end optical receiver’s RF drive level whether too high. Optical receiver’s RF drive level
determines the modulation, it also determines the system index (CNR, CTB, CSO). Designing should meet
optical receiver manufacture requirement.
If received optical power and optical receiver RF drive level are all normal, optical receiver RF output power
may be adjusted through ATT1.
